Herigonius K Impact Melt Flow

Grooves carved out by ejecta during the Herigonius K impact event provide channels for impact melt to flow outwards. Small cracks can be seen on the impact melt surface, possibly from contraction as the impact melt cooled. LROC NAC M135426635LE, image width is 500 m [NASA/GSFC/Arizona State University].

Impact melt is a common feature inside fresh craters on the Moon. Less common, but no less spectacular, are impact melt flows that were emplaced just outside their parent craters and flowed downslope. Because impact melt is fluid when it lands, it flows down the flanks of the crater until it reaches an impasse and pools in low lying areas. The impact melt flow in today's Featured Image has done exactly this. The surface that the impact melt flowed down appears grooved. These grooves were probably carved out by ejecta when the impact occurred. Soon after, the impact melt was deposited and was able to follow the grooves downslope until meeting an obstacle.

LROC WAC context image of today's Featured Image, located within the white box. Image width is 100 km [NASA/GSFC/Arizona State University].